1. Field of the Invention
This invention relates to high definition television (HDTV) and in particular to a coder and decoder for HDTV signals.
2. Description of Related Art
There has been proposed an HDTV coder/decoder (usually referred to as a codec) which consists of six parallel conventional definition (CDTV) bit-rate reduction codecs in parallel (i.e. six sub-codecs). Each codec operates on an appropriate block of picture area and the HDTV codec can operate at 140 Mbit/S. Although this proposal is attractive, it has the disadvantage that if it were to be adopted as a standard, any future implementation would have to consist of six parallel codecs. This standard may not be efficient when the speed of single codecs is increased to the point where an HDTV codec could be implemented with fewer parallel paths.